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Ultimate Secrets To Saltwater Fish

The Ultimate Guide To Keeping Happy,healthy Marine Life (fish, Corals And Other Invertebrates) And How To Optimally Set Up A Saltwater Aquarium And Maintain A Pristine Environment For Your Pets. Create The Perfect Environment For Your Marine Life and Learn: How to easily and cheaply prepare excellent quality water for your tank with none of the hidden sources of pollutants. What to do to completely assess your aquariums water quality in 7 easy steps that take 5 minutes. This is one of the most frequently underestimated keys to success that so many people just dont understand, by the time they get their water test results back from the local fish shop it's often too late. The truth about microorganisms in your aquarium: what they are, which ones are bad and how to enrich for the beneficial ones that can save you a lot of grief. Beautifully and easily aquascape your marine aquarium in 5 steps that take 30 minutes. What never to do regarding your aquarium equipment: the livelihood of your marine life could rely on this little known marine biologist tip. Banish aquarium problems for good by learning how to prevent them before they happen. Science has demonstrated that prevention can end up to 90% of disease outbreaks! The truth about cheaply setting up your marine aquarium, learn the key elements you really need and to avoid the unnecessary gimmicks and expensive add-ons. Slash the time and effort you spend on maintaining your aquarium, learn the absolute necessities you need to do and when. Everything else is just a waste of your precious time and money. Continue reading...

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Author: Andrej Brummer
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Aquatic Environments Seawater

With respect to extracellular fluid, animals in marine environments either osmoconform (have the same osmotic concentration) to seawater (1000 mOsm Figure 4) or osmoregulate at a lower osmotic concentration (usually 300-400 mOsm). In addition, they either ionoconform with respect to their extracellular fluid, having the same ionic composition as seawater, or they ionoregulate and maintain different ionic concentrations. Animals that conform to seawater do not have to overcome the problem of continual osmotic loss of body water to and gain of ions from the environment, but high ion concentrations adversely influence cellular metabolic processes. Most marine invertebrates osmoconform and ionocon-form to seawater, but a few osmo- and ionoregulate.

Biological features of the marine environment

We shall discuss later (in Chapter 4) how organisms in the sea may be influenced by environmental conditions, notably the temperature, composition, specific gravity, pressure, illumination and movements of the water. However, we have already said enough about the circulation of the oceans to indicate that the water is kept well mixed, and this ensures a generally homogeneous environment. The composition of seawater (see Section 4.3) remains almost uniform throughout its extent despite considerable differences in the rates of evaporation and addition of fresh water in different localities. The composition of present-day seawater may differ in some respects from that of the remote past but if so, marine organisms have been able to evolve and adjust to changing conditions. The body fluids of all the major groups of marine invertebrates are virtually isosmotic with seawater, and of a generally similar composition (see Section 4.3.1).

Types of Adaptations Relevant to Population Dynamics

In marine environments, most species produce propagules that disperse large distances in open ocean. For marine invertebrates and fishes, arrival at adult habitat (settlement) is characterized by larvae choosing to settle with resident conspecifics. This choice affects rate of conspecific aggression, group and individual survival, growth, and reproductive success.

Cluster sampling See sampling

Cnidaria A large phylum of aquatic, mostly marine invertebrates - the most primitive of the multicellular animals. Cnidarians are radially symmetrical and diploblastic, the body wall having two layers separated by a layer of jelly (mesoglea) and enclosing the body cavity (coelen-teron). The single opening (mouth) is surrounded by a circle of tentacles, which are

Genetic Analyses and Discovery of Cryptic Species

Cryptic aliens are species that were not recognized as alien in origin or, in some cases, not distinguished from other aliens. Many cryptic species are probably the products of recent evolutionary divergence, although some may be strongly conserved genotypes of ancient origin. Many examples of cryptic aliens involve marine invertebrates. Marine poly-chaete worms of the genus Marenzelleria, for example, are native to the Atlantic coast of North America.They appeared in coastal waters of Scotland in 1979 and in the Baltic Sea in 1985 (Bastrop et al. 1998). These polychaetes have since become a major component of coastal and estuar-ine habitats throughout much of western Europe. Mitochondrial DNA

Source Areas Revealed by Genetic Analyses

Among marine invertebrates, the colonial ascidian (sea squirt) Botryllus schlosseri is now a nearly cosmopolitan marine invertebrate that has been introduced to new coastal regions by oceanic ships. Botryllus is a fouling organism that grows commonly on the hulls of ships and is believed to be native to the Mediterranean Sea. This ascidian first appeared on the North American east coast in the early 1800s, apparently introduced by ships from Europe. Much later, in the 1940s, it colonized the west coast of North America from California to Alaska. Analysis of microsatellite alleles showed that Botryllus populations on the New England and California coasts were quite distinct, making it unlikely that west coast populations were introduced from the North American east coast (Stoner et al. 2002).Thus, it appears that the populations on the North American west coast are derived by an independent introduction from Europe or from Asian localities to which the species has been introduced from...

Chordates Including the Vertebrates

Not all chordates are easily recognizable as being closer relatives to us than, say, echinoderms. Two subphyla within the Chordates are marine invertebrates (Table 8.3). The subphylum Urochordata constitutes the tunicates. These include about 2000 species of filter feeders. Many, called sea squirts, are sessile. One group, called the salps, form meters-long colonies of transparent lemon-shaped bodies. Salps are brightly bioluminescent. The phylum Cephalochordata includes the 25 or 30 species of lancelets. Also called amphioxus, they resemble a small, translucent fish without fins or mouth or eyes to mark the head. They are common in sandy coastal waters around the world. Four species are found off the coast of North America. The boney fish include most of the familiar fresh- and saltwater fish. They have developed ray fins and a swim bladder, a gas-filled chamber below the spine that the fish uses to control buoyancy. The importance of this can be seen by considering the sharks, which...

The Cambrian Radiation and the Diversification of Sedimentary Fabrics

WITH THE CAMBRIAN RADIATION of marine invertebrates, sedimentary rocks on this planet changed forever. The advent of skeletonized metazoans introduced shells and skeletons as sedimentary particles, and the tremendous increase in burrowing metazoans resulted in the partial or complete mixing of sediment and or in the production of new sedimentary structures. Whereas constructional frameworks formed by stromatolites were common in the Precambrian (e.g., Awramik 1991 Grotzin-ger and Knoll 1995), metazoan reef builders first appeared near the Precambrian-Cambrian boundary, initiating complex reef fabrics in Early Cambrian time (Riding Study of Neoproterozoic and Cambrian sedimentary fabrics is further complicated by the presence of nonactualistic sedimentary structures (e.g., Seilacher and Pfluger 1994 Pfluger and Gresse 1996) and by the effects of changing biogeochemical cycles, which are reflected by isotope data as well as the distribution of specific facies types such as black shales,...

Agerelated differences

Much dispersal is natal dispersal, i.e. dispersal by juveniles before they reproduce for the first time. In many taxa this is constitutional we have already noted that seed dispersal in plants is, by its nature, natal dispersal. Likewise, many marine invertebrates have a sessile adult (reproductive) stage and rely on their larvae (obviously pre-reproductive) for dispersal. On the other hand, most insects have a sessile larval stage and rely on the reproductive adults for dispersal. Here, for iteroparous species, dispersal is most often something that occurs throughout the adult life, before and after the first breeding episode but for semelparous species, dispersal once again is almost inevitably natal.

Distribution And Abundance

Sponges may live in all types of coral reef habitats, but in reality they exhibit very patchy distributions, such that in one particular area they may form the dominant structural benthos, whereas in another adjacent area they may be practically absent. This is not unusual for marine invertebrates, where at small (local) spatial scales (i.e. encompassing different habitats within a single reef, up to groups of adjacent reefs tens of kilometres apart), spatial heterogeneity is common (in terms of both species diversity and abundance bio-mass), and has been widely reported for sponges across all ocean basins. Many factors may significantly influence local sponge distributions. Terrestrial influences, such as freshwater input, turbidity, sedimentation, light penetration, nutrient levels, food particle size availability and so forth have been found to explain differences between sponge faunas in the lagoon, closer to the land, and those living on the outer reefs. Geomorphological...

Barriers to dispersal

Barriers to dispersal may be relatively easy to recognize on land, for example water bodies and mountain ranges limit the distribution of many ground-dwelling species, and dry land is a barrier for many riverine species. In contrast, robust physical barriers are relatively uncommon in the ocean, and therefore oysters, clams, starfish, sea urchins and other species whose planktonic larvae can remain free-living for days, weeks or even months are theoretically capable of being transported across vast expanses of open ocean. Following on from this, it is intuitively appealing that long-lived larvae should have a higher potential for dispersal than short-lived larvae, and a number of comparative studies have supported this prediction. One example of this is sea urchins in the genus Heliocidaris. H. tuberculata has a planktonic larval stage of several weeks, and showed very little genetic differentiation between populations separated by 1000 km of ocean, whereas H. erythrogramma has a...

Reproduction And Life History

Have also been recorded, such as elimination of the free-swimming larval stage and embryos brooded in the maternal sponge before being expelled as young adults. Eight different larval types are known but few of these have been adequately investigated. Most embryos develop into free-swimming (lecithotrophic) or demersal crawling larvae, ciliated to a greater or lesser extent, 0.05-5.00 mm long, with a brief planktonic phase, short longevity (maximum of 72 hrs recorded), and, unlike most marine invertebrates, have no plank-totrophic stage.

Species Diversity and Invasion Resistance

Somewhat similar results have been obtained for communities of aquatic organisms. Working with communities of sessile marine invertebrates in New England, Stachowicz et al. (1999) created artificial communities of one to four native invertebrates by placing together tiles, each 2 by 2 cm in size, on which individual species were growing. In an array of five by five tiles, five additional tiles with a 1-week-old recruit of an alien ascidian (Botryllus schlosseri) were interspersed. Survival of the alien ascid-ian decreased in linear fashion from more than 60 to less than 20 with an increase in diversity of the overall community.

Aquaculture Waste Production

The rest of the N and over 70 of the P will be deposited into the sediment. The process takes place mainly in the area surrounding the culture installations, where the organic matter content of the sediment increases by up to 7-8 (dry weight). Under this organic-enrichment condition, high benthic microbial respiration can increase oxygen consumption in the upper layers of sediments and completely depletes oxygen levels below the first 1-2 cm resulting in anoxic sediments. This process results in emission of environmentally undesirable chemical compounds such as methane (CH4) and hydrogen sulfide (H2S). Additionally, remineralized nutrients (N and P) exacerbate marine eutro-phication, being especially relevant for N since, in oxygen-depleted environments, it is mostly released as bioavailable ammonia without undergoing aerobic denitrification to N2. Sulfide enrichment and oxygen depletion significantly reduce biodiversity of marine invertebrates (see Figure 2 for details).

Multipartner Urochordate Chimeras as Cooperative Foraging Units

Even more dramatic than cooperative foraging in pleometrotic ants is the tissue fusion (chimerism) ofgenetically distinct conspecifics in various marine invertebrates. Recent studies ofthe cosmopolitan tunicate Botryllus schlosseri have explored some ofthe fitness consequences of this ultimate joining phenomenon (Rinkevich and Shapira 1999). In this species, two genotypically distinct colonies (partners) may fuse through their peripheral blood vessels, provided they share alleles at a single fusibility histocompatibility locus (Weissman et al. 1990). Such bichimerical fusions yield no fitness gain for either partner (Rinkevich and Weissman 1992). In fact, a dramatic secondary allorecognition phenomenon usually follows fusion the morphological elimination (resorption) of one ofthe partners (Rinkevich and Weissman 1987). This fact alone suggests a major fitness cost to the loser in this resorption. Group benefits may favor this astonishing form of self-sacrifice.

Radioactive pollution

Seaweeds can concentrate radioiodine with great rapidity and fish absorb a variety of radioactive substances. In addition radioactive substances can bioaccumulate in marine animals in a similar way to heavy metals. The effects on marine organisms are not fully understood but may include genetic disturbances and increased mortality both in young stages and in adults. Interestingly, many marine invertebrates can withstand radiation doses that would kill people. Some deep-water marine shrimps, exposed to doses of natural radiation sufficient to debilitate people, remain unharmed. A variety of cancers in humans, such as childhood leukaemia, is linked to radiation exposure.

Measuring Recruitment

Environmental conditions often drive variation in recruitment. In most case studies, the amount of predation, climatic conditions (e.g., drought for plants or terrestrial animals, temperature in marine organisms, reduced light for trees), physical and chemical properties of the ecosystem (e.g., exposition to chemical inducers that reduce growth and survival of juveniles), the prevalence of various diseases, population density, habitat quality, the availability of refuges, and the intensity of interspecific competition all markedly influence recruitment. Most of the time, several environmental factors interplay to shape recruitment, and their interaction can either increase or dampen recruitment variation. For instance, in flatfish, variation in habitat quality has been reported to lower rather than to increase recruitment variability. Besides these ecological sources of variation, recruitment can also vary as a direct consequence of the life history strategy. For instance, the high...

Assessing the Role of Variation in Recruitment on Population Dynamics

The influence of variation in recruitment relative to variation in mortality or emigration in determining variation in population size and growth has been analyzed in several taxa living across a range of ecosystems. There is no consensus on the relative importance of recruitment. In most terrestrial vertebrates, adult survival typically varies much less than recruitment through time, space, or with population density. In marine ecosystems, the 'recruitment limitation hypothesis' states that recruitment patterns account for most of the temporal or spatial variation in population abundance of most species. However, some studies of tropical reef fishes and of marine invertebrates have reported that changes in postrecruitment mortality rate and postsettlement processes can be more influential than changes in recruitment rate. Several methodological issues might account for such inconsistencies. Before we can safely identify the ecological and evolutionary causes of variation in the...

Adaptations to Salinity

Stress tolerance is generally achieved through metabolic or physiological adaptations. Both plants and animals have a diversity of adaptations to various levels of salinity in the environment, as either hyper- or hypo-salinity can cause physiological stress. Osmoconformers are organisms that keep their internal fluids isotonic to their environment, that is, they maintain an internal salinity similar to their ambient conditions (e.g., most marine invertebrates, seagrass). Osmoregulators, conversely, maintain a constant osmotic pressure within their bodies by balancing water uptake and loss through the controlled movement of solutes across membranes between internal fluids and the external environment (e.g., most aquatic vertebrates, some marine invertebrates such as fiddler crabs). Organisms may have selective cellular uptake of particular salts, for example, preventing sodium but allowing potassium uptake (salt grass, cordgrass). Plants

Using clines to estimate dispersal

In a similar manner, evolutionary ecologists have begun to utilize clinal theory to estimate dispersal distances of organisms. This approach may become particularly useful to marine researchers, because most marine invertebrates produce hundreds to thousands of microscopic offspring per parent and as a consequence, there are few empirical estimates of larval dispersal of marine organisms to within several orders of magnitude. However, inferring mean dispersal distance requires a precise estimate of the selection coefficient (se), which is itself a logistically difficult task. Field-based experiments can sometimes detect rather strong selection coefficients, but weaker levels of selection are more difficult to measure. Laboratory-based experiments can be more sensitive, but in many cases, their results may not be generalizable to more natural conditions.

Ecological Controls

Suspension feeders may be epifaunal, infaunal or pelagic. They include sedentary animals like corals, bryozoans, brachiopods, many bivalves and the crinoids, all of which have well-developed hard parts and are thus common as fossils. Their main food supply is probably diatoms and other protists which rely on photosynthesis, and which can thus only develop in abundance very near the surface of the sea (Ryther, 1963). The pelagic larval stages of many marine invertebrates also feed on these protists and live with them near the surface of the oceans. These larvae are also an important part of the marine food chain. Much more of this (protist and larval) food supply is thus available on the sea floor in shallow water areas these are the areas, both today and in the Palaeozoic, where the majority of suspension feeders live.

Biosensor

For example, the concentration of organochlo-rines in sea water is in picograms per liter to a few nanograms per liter, in marine invertebrates this rises to tens of nanograms per liter, in mussels several milligrams per liter, and in the fatty tissues of marine mammals and predatory birds, hundreds of milligrams per liter. See trophic level.

Kairomones

Kairomones are not only involved in the food location of foraging organisms, but are also used by potential prey or host organisms to detect the presence of natural enemies. This type of kairomones, which elicit certain antipredator responses, has been described for a broad diversity of taxonomic groups including vertebrates (mammals, amphibians, reptiles, and fish) and invertebrates (arthropods, mollusks, cnidarians, and rotifers). Due to the better experimental accessibility, however, the majority of such responses has been recorded in freshwater and marine invertebrates, fish, and mammals yet, nearly nothing is known for birds and terrestrial insects. The chemical basis of predator-released kairomones is

PAH Toxicity

PAHs can degrade quickly via exposure to sunlight -in contrast, PAH half-lives in marine sediments range from months to years. In general, PAHs exposed to solar radiation can result in greater toxicity (phototoxi-city), as free radicals which react with oxygen to form reactive oxygen species such as singlet molecular oxygen are generated. These reactive species can then target and damage important macromolecules such as nucleic acids (i.e., DNA, RNA) and proteins. The reactive singlet molecular oxygen may potentially destroy gill or skin membranes of fish, impairing respiration. Photoenhanced toxicity has been reported in bivalve embryos, marine invertebrates, and fish.

Sea Grass Defense

Sea grasses growing in large meadows are targets of herbivory despite their low nutritional value. Their high content of phenols is discussed as a means to reduce feeding pressure, similar to terrestrial plants. Sea grasses depend on photosynthesis and consequently it is important for them to maintain the leaf surfaces free from other organisms such as marine invertebrates, bacteria, epiphytic algae, or fungi. The eelgrass Zostera marina produces zosteric acid 13 (Figure 2), a sulfated coumaric acid which very efficiently prevents the attachment of foreign organisms on its surfaces. The sulfate moiety is crucial for its bioactivity as an antifouling agent similar to other sulfate-containing marine compounds, for example, steroids from marine sponges.

The grazing rate

Bainbridge's experiments were not designed to elucidate the nature of attractive or repellent substances, but these did not appear to be associated with changes in the concentration of carbon dioxide or oxygen or pH. Positive migrations into concentrations of ammonia were observed. As this is the usual excretory product of marine invertebrates, its attractive effect might be partly accountable for the tendency of many small pelagic organisms to collect in swarms.

Test Methods

Acute toxicity tests are short-term tests designed to measure the effects of toxic agents on aquatic species during a short period of their life span. Acute toxicity tests evaluate effects on survival over a 24- to 96-hour period. The American Society for Testing and Materials (ASTM), Environment Canada, and the U.S. EPA have published standard guides on how to perform acute toxicity tests for water column and sediment-dwelling species for both freshwater and marine invertebrates and fishes. A list of the standard methods and practices for water-column tests for several species is presented in Table 2.1. The species most often used in North America include the fathead minnow (Pimephales promelas), rainbow trout (Oncorhynchus mykiss), bluegill (Lep-omis macrochirus), channel catfish (Ictalurus punctatus), sheepshead minnows (Cyprinodon var-iegatus), Daphnia magna, Ceriodaphnia dubia, amphipods (Hyalella azteca), midges (Chironomus sp.), duckweed (Lemna sp.), green algae (Selenastrum...

Ontogeny

Can change as animals grow and gape-limitation eases. Other animals change their diet with growth because predation risk declines with size, allowing them to use previously risky habitats. Still other species exhibit a fundamental change in habitat use as a result of life-history changes or dispersal (e.g., marine invertebrates with planktonic larvae that settle to become sessile adults).

Deepsea food supply

A further source of food available to benthic animals is dissolved organic matter (DOM) (see Section 4.3.3). The ways in which DOM can be utilized by planktobacteria, and their role in the 'microbial loop' and the food web, are described in Section 5.1.2. However, it is believed that some benthic animals can directly utilize DOM. Some shallow-water invertebrates can utilize dissolved amino acids but it is in deep-sea benthic animals that uptake of DOM is best developed. Pogonophoran worms do not have an internal alimentary system and part of their energy requirements are thought to be met by uptake of DOM. They also utilize symbiotic chemosynthetic bacteria (see Section 6.4.5). There is experimental evidence that many other marine invertebrates, though possessing feeding mechanisms which ingest solid food, are also capable of taking in aminoacids, glucose and fatty acids from dilute solution by direct absorption through the epidermis (Sorokin and Wyshkwarzev, 1973 Southward and...

Lineage sorting

In vertebrates, bisexual allopolyploid hybrid species are not uncommon in fishes and frogs. In addition, virtually all of the 70 unisexual vertebrate taxa that have been identified so far, which include species of fish, lizards and salamanders, arose following the hybridization of parental forms. More recently, hybrid speciation has been documented in marine invertebrates. Within the soft coral genus Alcyonium, A. hibernicum contains two groups of closely related sequences from the nuclear ribosomal internal transcribed spacer (ITS) region. One of these groups matched sequences that were also found in A. coralloides, whereas sequences in the other group matched those found in an, as yet, undescribed species that is currently designated A. sp. M2 (McFadden and Hutchinson, 2004). The most likely explanation for this pattern is that A. hibernicum arose following hybridization between A. coralloides and A. sp. M2. The conclusion that this species has a hybrid origin is further supported...

Species Selection

From this perspective, the reason some clades have been species rich throughout their history and others species poor is not due to members of one clade having traits that lead to higher Darwinian fitness at the individual or population level, but rather because the species-rich clade consists of species that themselves are likely to speciate at an enhanced rate. At some level, the argument has intuitive appeal - it makes little sense to argue that individuals from species-rare 'living fossils' such as horseshoe crabs are 'unfit' when compared to individuals from, for example, species-rich beetles. It is more likely that there is something about the ecology of phytophagous insects that makes them speciate at higher rates than generalist benthic marine invertebrates. D. Jablonski and other paleontologists have proposed that generalist or eurytopic taxa will tend to be less species rich than specialist or stenotopic taxa. Specific habitat requirements tend to lead to strong competitive...

Hypoxia and Anoxia

Entire taxa may be lost in severely stressed seasonal hypoxic anoxic zones. Larger, longer lived burrowing infauna are replaced by short lived, smaller surface deposit feeding polychaetes, and certain typical marine invertebrates are absent from the fauna, for example, pericaridean crustaceans, bivalves, gastropods, and ophiuroids. Increasing oxygen stress for the Skagerrak coast of western Sweden in semienclosed fjordic areas resulted in declines in the abundance and biomass of macroinfauna, particularly mollusks, suspension feeders, and carnivores. These changes in benthic communities result in an impoverished diet for bottom feeding fish and crustaceans.

Identifying prey

Provided that appropriate primers are available, prey items can often be identified by amplifying DNA from composite samples such as faeces, gut contents or even the entire predator, and then matching the characterized DNA to sequences or allele sizes from existing DNA databases. Deep-sea marine invertebrates provide a good example of animals whose feeding habits cannot be observed easily and whose prey are unlikely to be recognizable on the basis of morphology once they have been partially digested. In a recent study, Blankenship and Yayanos (2005) used universal cytochrome c oxidase I primers to amplify copies of this mitochondrial gene from the stomach contents of the deep-sea crustaceans Scopelocheirus schellenbergi and Eurythenes gryllus from the Tonga Trench. They found that both species fed on a wide range of prey, not all of which would have been carrion. This was an unexpected result because both species were previously believed to feed exclusively as scavengers, but the...

Discussion

Indeed, this toxic niche construction is one way to form a non-transitive competitive dynamic. Specifically, with regards to growth rate, the strain on the bottom of the totem pole (the producer) kills the strain at the top (the sensitive), thus creating a loop in the competitive interactions. Such non-transitivity has been found in other systems as well, including side-blotched lizards (Sinervo and Lively 1996), sessile marine invertebrates (Buss and Jackson 1979), and yeast (Paquin and Adams 1983). Theoretical work on non-hierarchically organized communities has shown that such interactions can promote the maintenance of biodiversity (Huisman and Weissing 1999 Huisman et al. 2001). Non-transitivity may be an important ingredient in the persistence of diverse bacteriocin communities, but it seems to require a partner to get the job done. This partner is population structure.

Trends in time

The most extensive data on temporal trends in macroevolution are from the fossil record, in particular, that of shelly marine invertebrates, which has been extensively documented. The data tend not to be analysed at the species level because of various inaccuracies and biases that are accentuated at low taxonomic levels.

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